01 - 
                Set oven to 425°F and line a tray with parchment.
              
              
              
                02 - 
                Massage lemon zest into sugar, then whisk it with flour, salt, baking powder, and soda.
              
              
              
                03 - 
                Mix chunks of cold butter into the flour mix by hand or with a pastry cutter until it looks like little crumbs.
              
              
              
                04 - 
                Stir buttermilk and egg together, then gently mix this into the dry ingredients till just combined.
              
              
              
                05 - 
                Shape dough into an 8-inch round, slice into 8 pieces, brush with buttermilk, and pop in freezer for 15 minutes.
              
              
              
                06 - 
                Bake for about 20 minutes till golden. Once cooled, pour the glaze over the top.